Blasting method and tamping cartridge with utilization of liquefied gases



June 24, 1930.

BLASTING METHOD AND TAMPING CARTRIDGE WITH UTILIZATION OF LIQUEFIED GASES Filed March 14, 1929 Patented June 24, 1930 UNITED STATES LEOPOLD LISSE, OF BERLIN-LIGHTERFELDE, GERMANY v BLASTING METHOD -A ND TAMPING CARTRIDGE WITH GASES Application ma March 14, 1929, Serial No.

This invention relates to'a blasting method and to the cartridge required for the same, specially with utilization of liquefied gases.

The novelty consists in the interposition of solid tamping over the entire length of the bore hole, said tamping at the deepest point of the bore hole having a dynamiteike'efiect, the tamping near the mouth of the bore hole possessing less strong dynamic 1 efi'ect. i i

' The novelty consists in the special con- .struction of the intermediate tamping cartridges, so that the evaporization products are absorbed by these intermediate tamping cartridges. -Another object is, to prevent reducing of the temperature of the gases from explosion, so that the gas volume depending on the temperature is maintained constant.

According to the new method different efiects can be obtained in one and the same bore-hole with the same kind of cartridge by the interposition of the solid intermediate tampings. For such cases two kinds of blasting cartridges had to be used hitherto,

i. e. cartridges of different compositions.

The new method consists in that the effect of the blasting cartridges at the deepest point of the borehole is differentiated or increased in comparison with the effect or the blasting cartridges in the upper portion of the bore hole by inserting between parts of the cartridge column a solid body (for instance salt-dust or similar camping cartridge's). If for example in a bore hole, three meters long at the inner end three or four cartridges, each 30 cms long,-i. e. a

charging column of 0,90 to 1,20 meters is used, three tamping cartridges, for-instance cartridges of salt dust, each 30 cms. long together 0,90 ems. long, are inserted and on these intermediate cartridges two or more blasting cartridges are placed, difierent fef+ fects of the two portions of the charging columns 'will be obtained at the ignition.

The blasting cartridgees in the inner end of the bore hole are enclosed from both sides,

i. e. by the wall of the inner end of the bore hole and by the salt-dust cartridges interposed between the two charges. The cubic charging density is consequently not reduced UTILIZATION OF LIQUEFIED 347,140, and in Germany October 22, 1926.

as hitherto by the hollow space between the inner charge column and the charge column near the mouth of the bore hole. The explosive detonates therefore with less alterations in the explosion space formed by the length of the charge column. The efliciency of the cartridges in the inner end of the bore hole remains constant, whilst the efliciency of the cartridges near the mouth of the bore hole is reduced as these cartridges, which rest at the 60 inner side on the intermediate tamping, have at the other side in the mouth of the bore hole an enlarged explosion space whereby the charge density is reduced. By the intentional enlarging of the explosion space a reduction of the etticiency is obtained, which is generally desirable at the mouth of the bore hole. With solid explosives the transmitting possibility is low and extends only over a few cms. According to the novel blasting method the transmitting capability is almost unlimited and extends over 2,4- meters .as experiments-have shown. It has been found that tamping cartridges of infusorial silica or mineral dust or salt fill-the 7 space sufiiciently and prevent reducing of the charge density, that however,-on the other hand, at the explosion salt-dust distributed in dust form generates extraordinarily great heat and causes consequently a reduction of so the temperature and'thereby of the volume of thegases.

- These intermediate cartridges must therefore be made from materials which participate in the detonation. It the relation 5 between the blasting cartridges, i. e. the quantity of the oxygen in, excess, to the numher of intermediate cartridges used is correct, at least 1 x 3, the intermediate cartridges, filled with wood-dust from grinding, are completely combusted by the oxygen in excess. If it is desirable to improve this combustion, the catalizers commonly used in the explosive industry, for instance metals and salts, specially metal additions being as much cheaper than aluminium, are preferabl employed. 10 to 15% of such metal ad itions areadded to the wood-dust from grinding, whereby the combustion is extraordinarily accelerated. 108

Theenvelopes of the intermediate cartridges are preferably made from porous and well permeable material, as filteringand blotting paper, in order that the gases in the bore hole may be readily absorbed'by the cartridges. These intermediate cartridges might have a hollow channel in which case the combustion will even be better at the moment of the detonation as the surface, onwhich the blasting gases act, is larger and the cartridge is more easily destroyed. Two embodiments of the invention are illustrated, by way of example, in the\ accompanying drawlng.

Fig. 1 shows a bore hole with three blasting cartridges a in the inner end, several intermediate tamping cartridges 6 on said blasting cartridges 0, and two blasting cartridges an on the intermediate tamping cartridges b.

As shown in Fig. 2, the blasting cartridges 0 and the intermediate tamping cartridges d might alternate, the intermediate cartridges 61 having a central longitudinal channel e.

For the intermediate tamping cartridges any oxidizable substances, organic or inorganic, with or without addition of a neutral mass may be used.

I claim 1. A blasting method with utilization of liquefied gases consisting in charging the bore hole alternately with impregnated blasting cartridges and with tamping cartridges composed of oxidizable substances.

2. A blasting method with utilization of liquefied gases consisting in charging the bore hole alternately with. impregnated blasting cartridges and with tamping cartridges composed of oxidizable substances and comburent salts.

3. Ablasting method with utilization of liquefied gases consisting in charging the bore hole alternately with impregnated blasting cartridges and with tamping cartridges composed of oxidizable substances, com urent salts and neutral substances.

4. A blasting method with utilization of liquefied gases consisting in charging thebore hole alternately with impregnated blasting cartridges and with tamping car- 'tridges containing wood dust, ammonium nitrate, and infusorial earth.

5. A blasting method with utilization of liquefied gases consisting in charging the -bore hole alternately with impregnated blasting cartridges and with tamping cartridges containing oxidizable substances enclosed in permeable covers.

In testimony whereof, I affix my signature.

DR. LEOPOLD LISSE. 

